Videos and photos shared widely on Facebook and Twitter have showed the women purportedly following the lead of a woman who was arrested for a similar demonstration in January.

The 31-year-old protester, known as the “Girl of Enghelab Street”, later identified as Vida Movahed, took off her headscarf on a street in the capital Tehran. She was detained for several weeks before being released from custody.

Women in Iran have been forced to cover their hair since the 1979 revolution, although they are usually sentenced to far shorter terms of two months or less, and fined $25.

More than 30 Iranian women have been arrested since the end of December for publicly removing their veils in defiance of the law.